Fluid pump



June 6, 1939. A, THOMSON 2,161,729

FLUID PUMP Filed Oct. 25, 1957 2 Sheets-Sheet lv WZ@ g4 /Q June 6, 1939. L, A, THOMSON 2,161,729

FLUID PUMP Filed 001. 25, 1937 2 Asheets-sheet 2 VV w .i F9 L JW f 'wtm I Patented `une 1939 PATENT OFFICE FLUID PUMP Leroy A. Thomson, La Crosse, Wis., assignor to Bump Pump Company, La Crosse, Wis.

Application October 25, 1937, Serial No. 170,882

3 Claims.

This invention relates to pumps and more particularly to positive displacement pumps.

One object of this invention is to provide a. new pump construction. Another object is to provide a pump which will operate eiciently at wide ranges of speed. A further object is to provide a pump which will deliver a smooth flow of fluids with very little pulsation. Another object is to provide a pump which is especially adaptable for use in the treatment of food products. Another object is to construct a pump which will have very little leakage under a standing pressure head. Another object is to construct a pump with separate driving and operating compartments. Another object is to provide a pump which is readily separable into elemental portions. A further object is to provide a pump construction which will prevent a compression of fluid between the impeller ends. A further object is to provide a pump which will be free of compression knocks. Other objects and advantages of this invention will appear more fully in the following description taken in connection with the accompanying drawings. In the drawings, wherein like numerals represent corresponding parts in the various figures,

Fig. 1 is a right hand end elevation of the pump incorporating features of this invention. Fig. 2

. is a left hand end elevation view. Fig. 3 is a 30 longitudinal vertical cross section through the pump with parts broken away. Fig. '4 is a 'View taken on the line 4--4 in Fig. 3. Fig. 5 is a view taken on the line 5'-5 in Fig. 3. Fig. 6 is a view taken on the line 6-6 in Figs. 3 and 5. Fig. '7 is a. three corner perspective showing one of the impellers. Fig. 3 corresponds to a section on the lines 3-3 in the other figures.

Considering the drawings in greater detail, the pump comprises a driving means, suitable impellers, and a housing I6 having inlet and exhaust openings I I and I2 respectively. The impeller housing is so arranged that the impellers or pistons always lock the chamber in a positive manner to prevent any pulsation in the movement of the liquid.

The pump housing I0 comprises an impeller housing I3, the impeller cover or faceplate I4, the gear housing I5, and the gear housing cover or faceplate I6. These parts are arranged to be secured together at abutting surfaces so as to maintain the elemental parts of the pump in a definite position. 'I'he impeller cover is aligned with respect to the impeller housing so that it will be maintained in a definite position by means of the dowel pins I1 and I8. These pins are arllatter of which is pivotally secured upon the gear housing 22. The upper and lower clamps are substantially of the same construction but are lo slightly different in size. The upper clamp I9 comprises two arms 23 and 24 pivotally secured to the boss 2| by the bearing pin 25. At the ends of the arms 23 and 24 away from the pivot 25 is secured a cam lever 26 coupled to the two arms by the pivot pin 21. The lever 26 is provided with cam surfaces as at 28 and is arranged so that it may act as a yoke encompassing the boss 29 on the cover member. After the yoke is dropped over the boss, cam lever 26 is turned gn in a clockwise direction tightening -the cam against the outer surfaces 30 and 3| to securely lock the cover to the impeller housing. 'I'he impeller cover I4has a similar boss 32 at the bottom. A pair of lever arms 33 and 34 are pivoted g, to the boss 22 on the gear housing by means of the pivot pin 35. The opposite ends of the twol arms are connected together by a cam lever 36 which is pivotally secured thereto by the cam pin 31. The cam surfaces 38 of this lever abut 30 against one face 39 of the boss and the face 40 of the cover. l

The gear housing is provided with a bottom flange 4I upon which the impeller housing member I3 is mounted and secured through its op- 35 positely extending base flanges 42 and -43 by means ofthe holdfast means 44. The opposite face 45 of the impeller housing is provided with a plurality of holes 46 receiving dowel pins 41 for centering the two parts with respect to each 40 other. They are then-securely locked together by the cap screws 48, extending through the downwardly extending flange 49 of the gear housing and into the abutting portion 50 of the impeller housing and the tie screws 53. Theabut- 45 ting faces 5I and 52 respectively of the gear' housing and gear housing cover are secured together by the'cap screws 54 and 55. It of course will be readily understood that gaskets 56 and 51 may be placed between the abutting faces of 5o theyimpeller housing and impeller housing cover, and between the abutting faces of the gear housing and gear coverrespectively. 'I'he impellers 58 and 59 are press-fitted upon their respective stub shafts 6I) and 6I andare pressed from right to y the bearings.

leftasiviewed in Fig. 3 until they abut against the annular iiange 62 integral with each stub shaft. The hub 63 of the impeller, is then keyed to the shaft by means of at least one Woodru key 64. The stub shaft is then inserted through the sleeve bearing 65 which is fitted into the annular bearing boss 66, the latter being integral with the impeller housing I3. The bottom impeller will also be mounted as just described in the same manner as described in connection with the upper impeller after which the impeller housing coveri"`f|4 willbe locked to the impeller housing. The impeller housing contains two similarly shaped hollow annular bosses 61 arranged to provide appropriate packing holders for the stub shafts. The impeller housing cover contains a similar set of oppositely extending bosses 68. After the parts have been assembled as thus far described, packing 69 is inserted about the stub shaft and in the counterbored recesses ofv the bosses 68 after which the packing is locked in place by means of the packing glands 10. Packing 1I is similarly arranged about the stub shafts within the counterbores of thevbosses 61 wherein it is secured in place by the packing glands 12.

The outer ends of the stub shafts are supported by ball bearings. cover is arranged with inner and "outer spaced walls 13 and 14. 'I'he inner wallsv 13 are provided with spaced circular recesses 15in: which theY hubs 63 of the impellerare received. .The two walls are spaced apart 'by the upper and lower cover frame portion `16 and|11 respectively. The outer wall 14 is/also provided with two spaced similarly shaped counterbores 18forsupporting The inner diameter ofthe bores 18 is sufficiently large to allow the packing glands 19 to be placed upon the stub shafts. The hole is then bored with a larger diameter portion 19 into which the outer annulus 80 of the bearing is received. The inner annulus-8| of the' bearing is fastened to theendwofthe shaft 60 f by means of the shaft nuts 8|', and is spaced from the outer annulus by means of the bearing balls 82. The bearings are finally retained in place by means of the bearing plug members 83 each havingA an annularly extending flange 84 ar- -ranged to iit within the recess 19 and to abut against the outer annulus of the bearing.

- These plug members are secured in place by a plurality of machine screws 85. The lower plug is similarly shaped and is secured in the same manner. It will be appreciated that the impellers and the various parts used to retain them in place are so organized as to be interchangeable, in other words, the entire impeller assembly for the upper impeller in Fig. 3 can be substituted for the lower-impeller in Fig. 3 and vice versa. In this manner, a number lof different parts for the pump may be very materially reduced.

-The impeller housing contains a recess 86 comprising two intersecting annular chambers 81 and 88 being annular iny shape in view of the central bosses 66. The central bosses are provided witharcuate oppositely facing recesses 89 concentric with the outer wall of the corresponding impeller chambers 81 and 88. The interconnecting Wall portions 90 of the housing are I substantially straight and parallel to each other.

The inlet and exhaustfpipes Il. and l2 are threaded for standard pipe connectionsand Ahave central bores 9I-which extend into the impeller chambers by means of the under-cut' portions 92. These port bores are cutlwith definite di- The impeller housing ypeller chamber.

vcondition which if present would cause an objectionable knock. p y

The operation of this positive displacement pump will now be described in greater detail. The impellers 58 and 59 are arranged to be driven in opposite directions as indicated by the arrows in Fig 5. The position of the parts as shown in Fig.'y 5 corresponds to approximately the middle of the'ir intake stroke for the impeller 58 and approximately the middle of the exhaust stroke for tl'ieimpeller 59. Assume the trailing edge 93 ofthe impeller 58 to have just uncovered the counterbore 92` and to have created a partial Vacuum thereby sucking in iiuid behind 4the face 93. Theimpeller continues to rotate in a clockwise direction and continues to draw fluid into thechamber 81 until the leading face 94 seals the inlet 92. The continued rotation of the impeller nally uncoversthe counterbo-re 9| allowingf the fluid to be forced through the outlet I2. With the impeller 58 at the beginning of its intake stroke, it will be observed that the lower impeller 59 is in a sealed position. On the one hand, resulting from the sliding engagement of the impeller with the boss 66, and on the other hand by the engagement of the end portions of the impeller 59 in engagement with the walls of its cylinder 96 at the points 95 andv 96. While the lower impeller is in a sealed position, the upper impeller is creating a vacuum causing fluid to be drawn into'the space left by the displacement of the impeller during its rotation. With the impellers in the position shown` in Fig. 5 the upper impeller is sealed against the lower boss at the point 91 while the lower impeller is sealed at the point 98. This arrangement allowing the two impellers to be sealed at the same time, together with the design of the port bores, prevents any oscillations of the pumped fluid in the im- The condition of fluid oscillation just mentioned is quite prevalent in the usual rotary pumps and is a condition which is to be avoided.

When the impellers are in a substantially horizontal position with their arcuate members facing downwardly, the upper impeller is beginning to take in fluid whereas the lower impeller has just completed its last intake and is about ready to begin exhausting iiuid. When the two impellers are in ythe horizontal position with their arcuate shapes facing upwardly the upper impeller has just completed its last intake and the lower impeller is just beginning to take in iiuid while at the same time completing its exhaust from the previous intake.

After the upper impeller has completed its intake it continues rotation and covers the port 9| and allows it to exhaust fluid which has been entrained behind the face 93. The leading face 94 then acts as the face of the piston forcing the fluid out of the pump. The continuous rotation of the parts creates a continuous series of cycles of intake and exhaust for eachimpeller.

In order to drive the impellers in an opposite direction a gear drive is provided which may be driven from any suitable means coupled to the driving stub shaft 99. This latter shaft is supported in the sleeve bearing |00 carried by the boss IOI of the gear housing and by the roller bearing |02 carried by the boss |03 of the gear cover. The inner end of the bearing |00 is sealed by the oil seal |04 and the outer end of the shaft by another oil seal |05. A standard spur gear |06 is fastened on the stub shaft 99 by a Woodruff key |01 and is arranged to mesh with the spur gear |08 keyed at |09 upon the driven stub shaft I I0. The right hand end of each of the gear stub shafts 99 and IIO is irregularly cut at II I, II2 respectively and arranged to engage a complementary portion on the shafts 60 and 6I. After the two shafts are placed in engagement the joint can be covered by means of the sleeve |I3 which may be locked by set screws to one or both shafts or which may be merely secured in place by a tie t.

The inner annulus II4 of the bearing |02 is spaced from the gear wheel |06- by a spacing sleeve |I5. The bearing is secured in place by the threaded plug member I I6.

The lower gear shaft I I0 is arranged to flt within a similar sleeve |00 and to be concealed by the oil seal |04. The lower bearing |02' is spaced by the gear wheel, by the spacing bushing I5 and is locked in place by the bearing plug I'I. `The outer end of the stub shaft I I0 is covered by the expansion plate I I8 which both seals the shaft and allows for any expansion which may occur.

The gear housing and gear cover form a closed oil reservoir II9 having a bottom drain opening |20 and a lling opening I2I. The oil level is maintained suflciently high so as to feed the oil ports |22 and |23.

The arrangement of the parts is so organized that the lubrication of the gear drive and the lubrication of the various bearings can be accomplished without allowing any oil or other lubricant to get into the impeller compartments. In this way a very eiiicient pump is provided which can be used in connection with foods such as milk etc. without any danger whatsoever of contamination being present.

Although the preferred embodiment of the invention is shown and described, variations coming within the true spirit and scope of the same are to ,be determined by the appended claims.

What I claim is:

1. A rotary pump comprising a gear housing, gears in said housing, extensions carried by said housing, an L-shaped member integral with one 0f said extensions, a pair of vparallel shafts connected to said gears, an impeller housing engaging said extensions and said L-shaped member, means securing said impeller housing to said extensions, a pair of impellers rotatable in said impeller housing and connected to said shafts, said impeller housing having an inlet and outlet port,

and also having an open side, a cover for said open side of said impeller housing, outwardly projecting arms carried by said cover, each of said arms having cam engaging notches, pairs of links pivotally carried by said impeller housing and said L-shaped member, a cam member pivotally disposed between each pair of links and engageable in a notch to detachably lock said cover in applied position, and an operating lever secured to each cam.

2. A rotary pump comprising a gear housing, gears in said housing, extensions carried by said housing, an L-shaped member integral with one of said extensions, a pair of parallel shafts connected to said gears, an impeller housing engaging'said extensions and said L-shaped member, means securing said impeller housing to said extensions, a pair of impellers rotatable in said impeller housing and connected to said shafts, said impeller housing having an inlet and outlet port, and also having an open side, a cover for said open side of said impeller housing, outwardly projecting arms carried by said cover, each of said arms having a cam engaging notch in the outer side thereof, one wall of each notch being substantially horizontal and another wall under cut and inclined to the vertical, pairs of links pivotally carried by said impeller housing, and said L-shaped member, a 4cam member pivotally disposed between each pair of links and engageable in a notch to detachably lock said cover in applied position, each cam member when in operlative position engaging in the angle between the walls of a notch, and an operating lever secured to each cam.

3. A rotary pump comprising a gear housing, gears in said housing, extensions carried by said housing, an L-shaped member integral with one of said extensions, a pair of parallel shafts connected to saidgears, an impeller housing engaging said extensions and said L-shaped member, means securing said impeller housing to said extensions, a pair of impellers rotatable in said impeller housing and connected to said shafts, said impeller housing having aligned inlet and outlet ports and an open side, a portion of said impeller housing forming a partition extending partly across the confronting ends of said ports, each of Said impellers being so disposed in said impeller housing as to project partially across a port and to engage against saidpartition, a cover for said open side of said impeller housing, outwardly projecting arms carried by said cover, each of said arms having cam engaging notches, pairs of links pivotally carried by said impeller housing and said L-shaped member, a cam member pivotally disposed between each pair of links and engageable in a notch to detachably lock said cover in applied position, and an operating lever secured to each cam.

LEROY A. THOMSON. 

